* New U.N. force to deploy from next month (Updates with formation of interim government)

By Crispin Dembassa-Kette

BANGUI, Aug 22 (Reuters) - At least 25 people died when a gold mine collapsed near the Central African Republic town of Bambari, a spokesman for the mainly Muslim Seleka rebels which run the mine said on Friday.

The mine at Ndassima is carved deep into a forested hilltop about 60 kilometres (40 miles) north of Seleka's military headquarters in Bambari.

It is owned by Canada's Axmin but was overrun by rebels more than a year ago and now forms part of an illicit economy driving sectarian conflict in the country.

At least 27 artisanal miners were buried in the collapse of the mine on Thursday and 25 bodies have been retrieved, Ahmat Negat, the rebel group's spokesman, said.

The mine collapse is the latest setback for the country, which has been beset by sectarian violence between the Seleka and Christian militia for over a year.

Newly installed interim Prime Minister Mahamat Kamoun named a government with five Seleka cabinet members on Friday in a bid to help stabilize the mineral-rich country.

A senior official at the Ministry of Mines confirmed the mine collapse and casualties. He said the mine did not follow regulations and miners were working in dangerous conditions.

"Nobody from our service is on the ground to regulate the miners so they dig without any rules. Lower than three metres it gets dangerous and with rain there can be collapses," the official, Georges Yacinth-Oubaouba, told Reuters.

At Ndassima, labourers toil under the gaze of Seleka gunmen to produce some 15 kilos of gold a month. This is worth roughly $350,000 on the local market, or double that in international trade.

Axmin suspended activity at the mine in late 2012 after rebels occupied its camp. The company has said since then that it was monitoring the situation at the mine. There was no immediate comment from the company.

NEW GOVERNMENT

The Seleka, a coalition that includes some fighters from neighbouring Chad and Sudan, seized power in March 2013, triggering sectarian violence with Christian militia in which thousands have died and more than a million people have had to flee their homes.

Some 2,000 French and 6,000 African Union peacekeepers have been deployed to Central African Republic but they have struggled to help the weak transitional government stamp its authority on the country.

Interim President Catherine Samba Panza took over after Seleka's leader, hardliner Michel Djotodia, resigned the presidency in January.

The Seleka initially rejected Panza's decision to appoint Kamoun, a senior advisor to Djotodia, as interim prime minister earlier this month, saying they were not consulted on his appointment and would not join any government he formed.

On Friday, however, Samba Panza pushed Kamoun to immediately form a government. His inclusion of five Seleka members in his 30-strong cabinet surprised some analysts.

"The positive thing is that the top military leaders of Seleka, those known to the international community ... as criminals or associated with crimes against the civilian population, are not part of this government," said Marcel Diki Kidiri, one of the country's leading intellectuals.

"As for the civilians who are now in government, we'll have to wait to see whether the actions they take in the coming months contribute to the country's stabilization," he told Reuters.

A 12,000-strong U.N. peacekeeping force is due to start deploying next month, with much of its staff coming from the existing mission in the country.

Most Muslims have fled the south of the country in the face of violence, creating a de facto partition, and some members of the Seleka leadership have pushed for this to be formalised. (Writing by Matthew Mpoke Bigg; Editing by Susan Fenton)